Various fluid packages are provided with valves for taps to allow fluid to be dispensed.
Many of these fluid packages are used in a disposable or semi-disposable manner. These types of packages are generally manufactured using economical materials and methods. Disposable or semi-disposable packages require valves to allow their contents to be dispensed. These valves must be manufactured with materials and methods that are similarly economical to those of the packages. This need for economically manufactured valves has created the field of plastic injection moulded valves.
Although it is desirable for packages and valves to be economical to manufacture, they are also often required to be highly reliable. For example, leakage of valves can lead to significant damage to packaged product inventories. Leakage of packages through the valves may also make a packaged product undesirable to consumers.
Thus, there is a continual need to reduce the cost of manufacture while maintaining reliability of these valves.
A variety of valves suitable for fluid packages are known. Most of these have a bore or conduit which is closed at one end by a movable valve element.
One valve known in the industry is disclosed in U.S. Pat. No. 6,360,925 entitled “Liquid Dispending Tap”. This valve has an opening in the side of a bore that is closed by a movable valve member. This tap has a ridged body which has an opening for dispensing liquid and is provided with a control member which moves a closure element towards and away from the opening inside of the body transverse to the axis of the body. The tap is provided with a button which, if depressed towards the body, actuates movement of a control member to uncover a fluid outlet. The body of the tap is approximately barrel shaped with the outlet in the side of the barrel.
The control member moves transverse to the barrel and toward or away from the outlet which is formed in the side of the body. When the barrel is closed the control member covers and blocks the outlet. The control member is actuated by a button that moves inline with the barrel. The tap includes an actuation mechanism that transfers force between the directions of movement of the button and the control member, which are perpendicular to each other. The mechanism also spring loads the control member against the fluid outlet so the valve is closed when the button is released.
This actuation mechanism is relatively intricate and requires careful installation within the valve. Relatively fine features are moulded into the body of the valve to provide mountings for the mechanism, and an end of the hollow body near the button needs to be sealed by a resilient membrane.
A limitation of this type of tap is that it requires careful and costly assembly, particularly where the actuation mechanism for actuating the control member via the button is concerned.
Another limitation of this tap is that the hollow body is sealed only by a resilient membrane, the design of which provides only limited resistance to the transfer of gases. This may allow eventual oxidisation of fluids within the tap.
Another limitation of this type of tap is that it requires relatively fine moulding features for the control member actuation mechanism within the body. This may possibly result in a reduced lifetime or increased cost for injection moulding tools for the tap. The fine mouldings and the spring loading function of moulded parts may also require relatively expensive materials to be used.
Another disadvantage of this type of tap is that it requires a minimum of four to five parts. There would be significant advantage in a tap which provided a similar function but which had fewer parts using low cost resins only.
A further disadvantage of this type of tap is that the spring load provided by the mechanism may provide limited sealing of the outlet by the control member, particularly where inward pressure on the outlet is concerned. This is due to the construction and use of a soft sealing valve seat.
Accordingly, it is an object of the present invention to overcome or mitigate some of the limitations in existing fluid taps or valves, or at least provide the public with a useful choice in fluid dispensing taps or valves.
It is a further object of the present invention to provide a valve for flowable material that requires only three parts, or at least provides a public with a useful choice in valves for flowable material.
It is a yet further object of the present invention to provide a valve for flowable materials that provides robust sealing of its outlet, or at least to provide the public with a useful choice in valves for flowable material.
Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.
As used herein the term ‘bore’ is intended to refer to a space formed by a member of the valve, where the space is adapted to receive another member of the valve and allow it to move along the space. The space may or may not be circular in cross-section.
As used herein the term ‘flow opening’ is intended to be inclusive of both an inlet or an outlet of a bore.
All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications may be referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art in New Zealand or in any other country.
It is acknowledged that the term ‘comprise’ may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, the term ‘comprise’ shall have an inclusive meaning—i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. This rationale will also be used when the term ‘comprised’ or ‘comprising’ is used in relation to one or more steps in a method or process.